Iran's influential hardline spiritual leaders have issued a fatwa, sanctioning the use of atomic weapons as a "countermeasure' against other nuclear powers. The fatwa, which for the first time questions the theocracy's traditional stance that Sharia law forbade the use of nuclear weapons, signals Tehran's stiffening resolve on the nuclear issue, The Sunday Telegraph reported today. According to a senior cleric, it is "only natural' to have nuclear bombs as a "countermeasure' against other nuclear powers, thought to be a reference to America and Israel.